Method of making a golf ball



A118 1, 1939. B. BOGOSLOWSKY 2,l6'7,869 n INVENT Boris Bogosiowsky "ORNEY Patented Aug. 1, 1939 UNITED STATE s .PATENT ormcla.v

2,1ev,ss minion oF MAKING n GOLF BALL Boris Bogoslowsky, New York, N. Y. Application September 15,1936, Serial No. 100,869

ici. 1st-ici i i3 Claims.

This invention relates to golf balls and is directed to a ball oi novel construction anda method oi making the same.

Golfballs are universally now made by wrap- W ping a rubber band or bands about a suitable core until there is produced a ballbody 'oi desired size, after which the resulting .structure is encased within a gatta-perche. cover.

This method oi manufacturing goil halls is open to a number' oi well-hnorvn disadvantages., For example, it is extremely dimcult with this liti procedure to maire a ball body wherein the core is positioned at the geometrical center oi the ball, and consequently, the ball body, after being wrapped, is not a true sphere and the center.' ci its weight is not at its geometrical center. it is, oi course, true that goli balls, as now made, have a surface which is spherical in shape, but in order to accomplish this result, the guttadit order to corrnziensate ior the deviation from true spherical form during wrapping oi the elastic bands, and also to compensate ior the ridges produced at the surta/ce oi' the body by the wrap-1 rlii ping oi such bands. By varying the coverthiclr-n percha covering must be ot variable thickness in ness to meet the requirements, the non-spherical ball vbody may be made to produce a spherical ball, but itV cannot correct the oil-,center condition oi weight oi the ball Yand in rnany cases 3@ tends to` aggravate it,

When a ball, wherein the center of weight is'y not positioned at the geometrical center of the ball, is struclr by a golf club, it will not'follow h atrue trajectory but will tend to wobble or gyrate 8b and produce an effect similar to a hoolrl or "sllce". lurtherniore,- when a ball' wobbles during its passage through the air, its resistance is increased and its length of travel is corrspond ingly decreased. 4U y the art and it is a common practice to subject every ball, after its manufacture, to appropriate These facts are recognized by those skilled in tests primarily intended to disclosewhether or` not the center of gravity of the particular ball is at the geometrical center thereof. Actual y'experience shows that such is seldom the case,A but manufacturers operate within-predetermined tolerances anda ball which tests :within these tolerances is considered a first-class ball. Balls which test close to but without the tolerances are sold as cheaperl or inferior balls,z` jbut under prior practice there is a large 'percen age of balls which are wholly unmarketable. 'I `'ide Vfrom the questiono vcenter o! gravity and the. effect of a cover gcffvariable thickness concerned. l

thereon, it is well recognized that guita-perche, or balata is-practically non-elastic, and when a cover' thereof is of 'variable thickness, the edect oi a given stroke will depend upon that portion ofthe ball which may be struck. Consequently, 5 with balls as now made, uniformity in edect ot the propulsive stroke is questionable. Moreover, gatta-perch@I while hard and tough, is obviously no strongerthan itsweakest point which is generally its point of minimum thickness; When W such a cover is subjected to the stresses ci inx1 herent, internal elasticity oi the ball body, it is not uncommon for the cover to be fractured and split at this point 'oi weakness. My research and experimentation in connec tion withballs of the character specified con Vinces me that conventional methods oi manu facture are wrong in principle and that innerenn priate changes in such methods are highly dem sirable. l also concluded that the ball in present-day universal use is 'wrong in principle ior several reasons. For example,- when a `so--called wrapped ball is subjected to impact, the corre-1l spending hattening must talreplace through relative movement between consecutive wrappings g oi the elastic bands which enter into its construction', and Where there is such relative move--1 ment or shifting, there must necessarily be rnechanical friction. Such mechanical friction is `also present when the ball reacts to reassume its itil original i'orm, and this `friction, which is unduesgconsiderable power and must be considered asy waste power insofar as effective propulsion is V l iin A further effectof these conditions will be appreciated, particularly if it is borne in mind that the exterior wrappings of the elastic bands are encased within a practically non-elastic coat ing of gutta-percha. The said elastic bands, d when the ball is played, tend to stretch or retract but they are held tightly by the gutta-perchaor balata cover, and consequently the tendency is to break the cover ,at its Weakest point.

With the foregoing considerations in mind, the invention has several objects, among which may be enumerated: method whereby agolf ball may be made more economical than heretofore; a golf ball wherein the center of gravity will be, to all intentsl and purposes, at the geometrical center of' the balli a golf lball wherein the cover,

uniform tension.

body, all internal parts of which will be under substantially uniform radial compression and under substantially uniform circumferential tension, as will hereinafter be more fully explained.

Through the attainment of these objectsand others which will be presently described, I am able to economically and efficiently manufacture a golf ball without appreciable internal, mechanical friction in the body ofthe balls structure, eliminate ununiform thickness of the cover, and attain'uniformity in reaction of all parts of the ball to propulsive force.

In practically carrying out the method of! this invention, I start with preformed and substantially cured spherical sectors of elastic, compres-- sible material, such as rubber, so shaped that when uniformly and collectively compressed on all radii by suitable molds, either with or without a central core, they may be distorted into a ball body of spherical form and, while thus held under compression, they are secured to one another in such a way as to preclude their return lto initial shape when the external pressure of the mold is relieved. When the mold is open, however, the inherent radialcompression of the ballbody will set up a. pronounced circumferential tension through all parts of the body, adapted to effect abalanced condition with the radial compression o'f the body, serving to maintain and elastically hold the body in spherical form. The body thus produced is. encased within a cover of gutta-percha or the like ,of substantially uniform thickness. l

Features and advantages other than those hereinbfore enumerated will appear from the following detailed description Aand claims and from the accompanying drawings.

In the drawings, I have shown various methods of practicing the present invention and the re. sulting ball, but these showings are` to be understood as illustrative only, and not as-dening the limits ofthe invention. n

vFigs. 1 and 2"illustrate the ciple of the invention.

Figs. 3 and 4 are diagrammatic views showing illustrative modified forms of the method of this invention'.

Figs. 5, 6, 7 and 8 show successive steps in the method as shown in Fig. 3.

Fig. 9 shows the nishedball.

Figi'lO 'is a view similar to Fig. 3 and Fig. 4 but showing a further modied form of 'the method of this invention.

'Figa 11 and 12 showa modied method of procedure. 4

Fig. 1 and Fig. 2 illustrate diagrammatically the principleof this invention. Fig. 1 shows a cross section of aball -in which all th`e radii r are under compression. It is obvious that 4in order to maintain truly spherical form all these radii should be under the same compression forcesl and should be of equal length. `It is also obvious that .in order to maintain this radial compression, all the circumferences C1, C2, Ca throughoutl any) diametrical section of' the ball`should be under geometrical prinoperating If such a` ball is cut in two on any diametrical plane the circumferential tension and radial compression will be released vsimultaneously and all the half-circumferences C1, Cz, Ca will contract, while all the radii r will expand; and two equal hemispheres ofball Fig. 1 will assume'the form .of two equal spherical sectors of Fig. 2. Radii r,

r before the ball'was cut, were under equal compression vand were of equal length; therefore radii R of spherical sectors lalso will be equal in length to one another. If the compression ratio 'is .r then radii R=:l:r.` On the other hand, the

toral body.

But V1` is equal to V2; therefore l' f In other words, in order to produce a ball with radial compression z, two sectors should be preformed ofA elastic material with the radius R=r.r,

and the height of their segments h should be equal to These geometrical relations give fundamental explanation of this invention, and with the help of these formulae, the ball could be produced with desired radial compression and corresponding circumferential tension.

In practice, the form of spherical sectors might be modified as it will be hereafter shown; nevertheless with modification for all practical purposes, a satisfactory ball could be produced with' internal stresses desired.

The general method of the present invention is graphically illustrated in Fig. 3 of the drawings. Here two sectors I, of compressible elastic material, arel shown. These sectors are identical with one another4 and each constitutes a sector of a sphere of such larger radius than the ball body to be formed that when said sector is`subjected to substantially uniform pressure along' all of its radii, it may be compressed -and deformed intoa sernispliere of the 'radius of the ball body. When these two sectors are positioned with their apexes in coincision, either actually 'or geometrically, as -the case may be, and radial vpressure is -applied to the said sectors through the use of appropriate dies, said sectors may be progressively compressed' in a. radial direction, through an infinite number of' shapes, until they respectively 'partake of the iinal shapes indicated vvat 4 in Fig. 3, and which shapes are respectively semispherical. For the purpose of graphic illustration, two intermediate forms, 2 and 3 are shown'.l Thus, as radial pressure is applied ony Athe sectors I, they are compressed into the shape indicated at 24 wherein their major circumferential arcs are increased while their radial'lines 5 are caused to bulge as indicated at 6. Continued application of radialipressure forces the sectors tothe position 3 wherein their circumferential arcs are further increased and tne lines 1 are further bulged to such extent that the saidlines of the respective sectors will contact. with one lfinally forced into-the. positions indicated at 4 to bring the lines 8 into contact with one another throughout the entire diameter-of the resulting semispheres, so that said semispheres collectively constitute a figure of spherical form, all parts of which are under relatively high radial compression.

If the said radial planes of the respective semispherical bodies `are thereupon firmly united to one another throughout their entire extents, Aand that external .pressure which has forced them vinto this condition is relieved, the said sphere will autogenously tend to radially expand uniformly in all directions, and in so doing will place all portions of the body thus formedvunder circumferential stress, which, in the preferred i pression and `under circumferential or tangentiti form of this invention, is substantially uniform vthroughout the entire body.

There will thus be present in the vsaid body a balanced condition of radial andv circumferential stresses, acting throughout the entire molecular structure of the body'. In other words, every molecule of the body will beunder radial comtial tension, and such compression and tension will be in substantial balance so as to tend to maintain the true .spherical contour of the entire rnass.Y

Any force, such as the impact of a golfclub, which serves tol disturb this balanced condition will, upon secession of application of the force,l produce a reaction serving to bring about a re-u turn of suchbalanced conditions, and it is by virtue of these :facts that the ball of this inven 'tion is able to function satisfactorily as a golf ball and produce, along with other features hereinafter explained, a highly satisfactory coemcient of restitution.

In the showing of Fig. l, the method is the same as described inconnection with Fig. 3but with the exception that the preformed sectors,

which are to form the ball body, are pressed against and about an interposed spherical portion d which. in the finished ball, constitutes a center filler. It will be noted, however, from Fig. 4 that f the center of the spherical part 9 is at the jgeo-- metrical center .-...of the sectors i, so`that when the sectors l are compresse'das described in connection with Fig. l, all parts of the sectors i will be placed under uniform radial compression throughout/ with the resulting uniform cir cumferential tension. f

In practically carrying out this invention, the sectorsl may be made of any appropriate com-A pressible elastic material, such, Afor example,y as

natural, artificial, or synthetic rubber, while thel spherical portion 9 may be. made of metal, rubber, or any other appropriate material which will stand the pressure to which this part must be subjected,.without,squeezing out or disintegra tion. Furthermore, in Fig. 4, the sectors l have 'been referred to as separate from one another and from the part Q, but itis possible in practiceto make these partsintegral with one another and in some causes it is more convenient to do so.

I have referred to the fact that after the sectors are .compressed into semispherical form, they are secured together along vtheiry common diametrical plane.' The manner of accomplishing this result may vary depending upon the matebut when acting upon rubber blanks, this result may be satisfactorily accomplished through vulldesired shape and either separate or integral as i may be preferred, and thereupon vulcanize them to a point which-is preferably slightly under complete vulcanization or curing. In this condition, the sectors are manipulated in appropriate molds under pressure as hereinafter explained in detail, with unvulcanized rubber layers covering the conical surfaces of the sectors, and after 'the sectors have been compressed fully to formthe spherical-body of the ball, a vulcanizing step is carried on which serves to vulcanize said un.-` vulcanized layer of the 'rubber in the joint between ,the sectors, and at the same time produce unity between the two sectors In this way I obtain a substantial, homogeneous engagement between the sectors at the joint with proper vulfcanization in this zone and without over-vulcanizing the rubber in the sectors themselves.A

In Figs. 54), l have shown consecutive oper-- ating steps in the making of a ball in accordance with the method herein disclosed.I In Fig. 5, two sectors i of the character. shown in Fig. d, with an interposed spherical center d, are positioned between molds lll and l l, these molds being com'- .plernentary and here illustrated in retracted position. vl'Ihe said molds have rnold chambers il, complementary to one another and preferably substantially spherical in shape. ,The sectors are shown in position in the mold cavities in the condition in which they were preliminarily to increase the arc of their' circumference and bulge their radial surfaces.

Fig.- 'l shows a further stage in the closing of the molds, the stage corresponding to aboutthe position@ of Fig.. d, and Fig. 8 shows themolds almost fully closed to correspond with the position d of Fig. d. Whilethe molds are held in this closed position, the layer of uncured rubber tit;

` l t, either natural or synthetic, which was smeared upon the radial faces of the sectors, is vulcanized lto cause said faces to firmly adhere to one another and become, in effect. homogeneous; Heavy lines I4, Ill show overflo-wof excessof uncured rubber. This overflow may easily be trimmed vafter the ball is taken out of the mold.

At the conclusion of the vulcanizing operation,

the molds are first cooled tovgive. full strength.

to' the vulcanized seam and then the 'mold sections -are separated. Coincident with thismechanical operation the molecular structure of the component parts ofthe resulting mass seek to return to their initial condition and in so doing .set up the balanced condition of radial and cil.-v cumferential stresses towhich I Ahave referred.

The product of the operating steps described is asolid spherical rubber ballbody with or without a cre,rand wherein. thefcenter of gravity will be at the geometrical center of the ball or so close thereto that any variation will be .negibibla Y- y The layer I3 of non-vulcanized rubber after vulcanization will be subjected to tension and rials employed and upon commercial expediency;

theoretically it will stretch; but the thickness of this layer is practically so small that this stretching does not seriously affect the spherical form of the ball, though, if necessary, the shape of the mold may be made such that it will correct this situation. g

The spherical ball body with inclosed core is thereupon tumbled or buffed and provided with a cover I5 of gutta-percha or any other appropriate material to produce the finished ball shown in Fig. 9.

It will, of course, be understood that the exterior design of the cover may be conventional and it may be provided with dots, depressions,

or any other suitable or conventional surface or-` namentation or design, such as is commonly used on golf balls. It is important to note that the ball body as it comes from the' mold will be spherical in form and consequently the cover may be of uniform thickness throughout its entire extent in contradistinction to that pronounced variation in thickness found in wrapped golf balls as heretofore made.. Consequently, said cover will be of uniform strength throughout and will uniformly transmit impact received at any point in its surface to the inclosed ball body. It

will be also noted from Fig. 9 that, when the.I

respective sections are vulcanized together, the sections become substantially homogeneous throughout. Consequently, it is possible to make a ball which will be geometrically spherical and which will have balanced radial and clrcumferen-` tial stresses throughout, as hereinbefore explained.

In the foregoing description of the method, `the sectors I have been referred to as having straight line conical faces. Itis possible, howevento make these `faces other than of straight line conical form and I have shown in Fig. 10 sectors wherein the faces I6 are somewhat convex-concave.

When such faces are employed, the method is carried on as hereinbefore described, but the said `faces of the respective sectors may not come into face abutting relation throughout, but may leave, at the conclusion of compression in the: molds, concavities II which are canized rubber or other adhesive whichis 'to be used to secure the sections together, but the y concavities should be closed at the outer circuml. ference of the sphere so as to. entrap`the binding 65 the preferred form of ball hereinbefore described.

material shown at I8 which may be thereupon vulcanized to produce a proper bond between the I sectors at the joint as will I :ael readily understood. The nished ball is substantially the same as The molding dies, which-I described, may have smooth.

have hereinbefore inner surfaces or cavities of substantially semi-spherical form. I'

find in some cases, however, when operating with dies of this kind, that thereis a tendency to trap air within the cavities during the compression of the sectors and if this trapped air is not permitted to-escape, a deformed finished ball body. l Therefore, in practice, I preferably provide appropriate means for venting the cavities to permit of the escape of this air, This venting may be accomplished in` any one of several different ways, but, for the purpose of illustration, I have shown in Figures 5-8, the mold cavitiesIZ as'provided on their inner faces 4with venting channels 22 through which the air can Vescape for the purposes stated. The venting is preferably employed with molds of the character shown in Figures 5-8, but is not it has the Itendency to produce` necessary with molds of the character shown in l 'adapted to compress the sectors similar to I, I

of Figure 5, independently of the outer portions 20, of the mold. When said sectors are compressed this way, they will assume the form 2 I, 2 I. After this operation, the molds 20, 2l complete the forming operation as shown in Figure 12 and the ball assumes the finished form substantially as described above. VThis method permits of the introduction of still higher stresses in the body of the ball if this is desired.

In the foregoing detailed description, I have set forth the invention in its preferred practical form and have described in detail the invention with respect to the making of a golf ball to which the present invention is particularly appropriate. It is possible, however, to make other balls orball bodies than golf balls according to the present invention, and the. invention is to be understood as not limited to a golf ball alone. This disclosure which I have made is of the preferred practical forms of the invention, but'the'invention is to be understood as fully commensurate with the ap" pended claims. A V

Having thus fully described the invention, what I claim as new and desireto secure by Letters Patent is: I N,

1. 'Ihe method of making a ball, which comprises the steps of applying external pressure to pre-formed solid elastic sectors of substantially conical shape and of predetermined radius to force said sectors collectively into a-ball'body of substantially spherical form and of lesser radius than said-pre-formed sectors, and securing jux- 'taposed faces of the respective sectors to one another while the external pressure is maintained.

2. The method of making a ball which comprises the steps of externally compressing preformed solid elastic1 sectors of substantially conical shape and of predetermined radius to radially compress andcircumferentially expand the sectorsV sumciently to produce a spherical ball body of y smaller radius, with the radial faces of the sectors in substantial contact with one another, securing said faces to one another while thus compressed, and thereafter relieving the externally applied pressure to permit the radial and circumferential' -radius, -with the radial faces of the sectors in substantial contact with one another, securing said faces to one another while thus compressed, and thereafter relieving the externally applied pres'- sureto permit the radial and vcircumferential molecular stresses of the resulting ball body tol come into substantially balanced condition.

4. Themethotd of making a ball body, which comprises radially compressing pre-formed solid `rubber sectors of substantially conical shape and of predetermined radius to radially compress and circumferentially expand the sectors sufliciently to contact with one another, and vulcanizing said with one anothen/and prises radially compressing,

` to the rubber and while Y terminen radius;

radial faces to one another while the external pressure is maintained.

5. The method of making a ball body, which comprises radially compressing pre-formed solid rubber sectors of substantially conical shape and of predetermined radius about an interposed core to radially compress and circumferentially expand the sectors about the core sufiiciently to produce aspherical ball body of smaller radius, with the radial faces of the sectors in substantial contact vulcanizing said radial le the external pressure is faces to one another w maintained.

d. The method ot 'making a ball, which com'- prises radially compressing, through the application of external force, pre-formed solid rubber sectors of substantially conical shape and oi predetermined radius, vulcanized sumciently to'lmpart substantially full elasticity to the rubber, in creasing such compression until the radial faces of said sectors come into substantial contact with one another to form a. ball body oi lesser radius,

and yulcanizing said faces together while the external pressure is maintained.,

"i, The method oi ma ng a ball, which cornthrough the application oi external force, pre-formed solid rubber sectors of predetermined. radius, vulcanized suhiciently to impart substantially lull elasticity a quantity of unvulcanined rubber is present upon the radial faces oi the sectors, increasing such compression until the radial faces'of said sectors come into 4substantial contact .with one another to iorrn a ball body oi lesser radius, and thereupon vulcaniaing the unyulcanized rubber between vsaid faces while the external pressure is maintained..

d. The method of making a ball body, which comprises compressing, through the application oi external pressure, solid elastic sectors of substantially conical shape and of predetermined radius into a ball body of spherical form and lesser radius, and uniting all juxtaposed parts of the respective sectors' to one another while .under such external pressure.

il. The method oi making a ball, which comprises the following steps'in the order stated; urst, pre-forming solid rubber sectors of predethen vulcanizing said sectors; then applying unvulcanized rubber to the radial faces of said sectors; then assembling said sec--v tors .on a common center; then applying external pressure to the assembly toradially compress said sectors with resulting circumferential exy pansion of the sectors until they collectively externally applied pressure assume a substantially spherical form of smaller diameter with the radial faces of the sectors in substantial contact with one another, then vulcanizing the said unvulcanized rubber, while saidV vspherical form is retained, then cooling the Y product, and thereafter relieving the same of to permit the resulte ing radial and circumferential stressesA of the resulting ball body to come into substantially balanced condition.

10. The method of making prises the following steps in rst, pre-forming solid rubber sectors of predetermined radius; then vulcanizing said sectors; then applying unvulcanized rubber to the radial faces of said sectors; then assembling said seca ball, which lcomtors on a common center; then applying external pressure to the assembly to radially compress saidsectors with resulting circumferential expansion of the sectors until they collectively assume a substantially spherical form of smaller diameter with the radial faces oi the sectors in substantial contact with one another; then vulcanizing the said unyulcanized rubber, while said spherical form is retained; then cooling the product, and thereafter relieving the same oi eirternally applied pressure to permit the resulting radial and circumferential condition; thereafter roughening the surface ol the resulting bali body, and applying a suitable cover thereto. I

il, 'l'lie method oi mailing a ball, which comprises the following steps in the order stated; hrst, pre-forming termined radius; thenvulcanizing said sectors; then applying unvulcanizecl rubber to the radial faces oi said sectors; then assembling said sectors on a common center; then applying eater nal pressure to the assembly to radially compress said sectors about an interposed solid core with resulting circumferential expansion of the sectors until they collectively assume a substantially spherical forni of smaller diameter with the radial faces of the sectors in substantial contact with one another, then vulcaniaing the said unvulcanized rubber, while said spherical form is retained,

then cooling the product, and thereaiter relieving the same of 4eruternally applied pressure to permit thei resulting radial and circumferential stresses of the resulting ball body to come into substantially balanced condition. y

l2. lin the method of making a ball body, the step which consists in collectively compressing into spherical form two pre-formed elastic blanks. veach of which is of substantially the form of a spherical sector of substantially conical shape and has an unstressed volume substantially equal to the volume of the stressed semispherc of the resulting ball body.

13. The method of making a ball body which comprises radially compressing pre-formed solid 'elastic sectors of predetermined radius within dies to radially compress and circumferentially expand 'the sectors suiiiciently to produce a spherical ball body of smaller radius with the radial faces of the sectors in substantial contact with one another, venting the dies to preclude the entrapment of air during the compression of said sectors, and securing the radial faces of the sectors to one another while the external pressure is maintained.

BORIS 'BOGOSLOWSKY.

the order stated;

stresses of the result-- ing ball body to come into substantially balanced` solid 'rubber sectors of predelil lill 

